1. Field of the Invention
The present invention is related to water closets and, more particularly, is directed towards a mechanism for permitting the user of a toilet to select either a relatively small or relatively large volume of water for each flushing operation.
2. Description of the Prior Art
Many water level control systems have been suggested in an earnest effort to enable the user of a toilet to control the amount of water required for each flushing operation.
Some such systems operate by filling the water tank of the toilet to the same level after each flushing operation. Water is conserved by controlling the length of time that the outlet valve is opened in order to control the amount of water released from the tank to the bowl.
Other systems, in contradistinction, rely upon control of the inlet valve to thereby vary the total amount of water stored within the tank. In these systems, the outlet valve operates in a normal fashion to simply deliver to the toilet bowl all water contained within the tank when the toilet is flushed. Water conservation is achieved by filling the tank with only so much water as may be necessary to flush the wastes from the bowl.
Prior art United States patents of which I am aware which are illustrative of mechanisms which operate according to the first above-described mode of controlling the outlet valve include: U.S. Pat. Nos. 2,724,838; 3,141,177; 3,758,893; 3,839,746; and 3,894,299.
I am also aware of the following United States patents which illustrate examples of devices whose operation is based on the second above-named water conservation principle, i.e. that of controlling the inlet valve to the water tank: U.S. Pat. Nos. 3,385,317; 3,906,553; 3,945,057; and 3,956,777.
Each of the devices described in the cited patents suffers from one or more deficiencies which hinders their wide-spread use and adoption by the average consumer. Most of the mechanisms and devices are either too expensive, too complex to either manufacture or install, require internal rather external control, or simply do not provide the degree of control necessary to insure reliable and worthwhile operation.
There exists a further deficiency which is common to all of the devices described in the patents above-cited. That is, each may be utilized only in combination with conventional water closet float mechanism which, generally speaking, comprise a hollow, generally spherical float which is attached to the end of a horizontally disposed float lever which controls, at its distal end, the inlet valve of the toilet, cutting off the inlet valve when the float has risen to a predetermined height.
There is, however, in widespread use today another class of water closet mechanisms which differ substantially from those above-described in providng a float which is vertically movable along a vertically disposed guide member that extends through a guide-receiving aperture formed in the float. Examples of such mechanisms can be found in U.S. Pat. Nos. 3,319,913; 3,428,966; 3,429,333; and 3,576,199, and are known to be marketed under the trade name "FLUIDMASTER". They enjoy wide popularity due to their superior valve construction, ease of installation, quiet performance, and overall high reliability.
However, to the best of my knowledge, no one has yet proposed a practical water-lever control device which may be utilized in conjunction with the vertical float type of water closet. In order to be practical, such a device should be easily adaptable to existing toilets, economical to manufacture, of extreme simplicity, and reliable in operation.